Fig. 2

Overview of the BCL2 family and the regulation of cytochrome c release. a In unstressed healthy cells, several mechanisms, including canonical and non-canonical functions of BCL2 family members, prevent MOMP and release of cytochrome c from mitochondria, including the retrotranslocation of BAX/BAK and the limited availability of BH3-only proteins at mitochondrial membranes and preventing mitochondrial Ca²⁺ overload. b Upon cellular stress, BH3-only proteins become available at the mitochondria and facilitate BAX/BAK oligomerization, leading to MOMP. This is also facilitated by increased Ca²⁺ signaling including Ca²⁺ transfers from ER stores towards mitochondria. Created in BioRender